ALmix Dratch Hybrid Plant | How it Works

The dratch plant process begins with a set of cold feed bins that bring virgin materials to a counterflow drying drum where they are dried and superheated. As material reaches the downhill end of the drying drum, it enters a Y-chute, where the dried material can be diverted to a batch plant tower’s hot elevator, or to the inlet chute of a mixing drum, as seen in ALmix Duo Drum plants. This process is what makes the dratch plant a hybrid of some of our best technologies. Learn more on each below.

Batch Tower: Once the heated material is taken up to the top of the batch tower using the hot elevator, the material follows the standard ALmix batching process inside the batch tower. This includes screening into hot bins, individual weighing of each type of aggregate, metering of liquid AC and dust and final mixing in the batch tower’s pugmill mixer.

Mixing Drum: Once inside the mixing drum, the virgin aggregate is mixed with dust, RAP and liquid AC. This design prevents expensive materials from the direct heat of the burner flame, and also prevents the creation of “blue smoke” by keeping liquid AC and any AC present in the RAP away from the burner flame. A small fan pulls connected to the end of the mixing drum pulls out any hydrocarbons from the airstream and brings them to a manifold on the main burner where they are incinerated by the heat. The finished hot mix asphalt is discharged from the end of the mixing drum and taken up to hot mix silos using a drag conveyor.